HONG KONG, Aug 30 (Reuters) - Tokio Marine Holdings Inc is in exclusive talks to buy RHB Bank’s general insurance unit in a deal that also includes an agreement to distribute the Japanese insurer’s products through the Malaysian lender, people familiar with the matter told Reuters.

RHB, Malaysia’s fourth-biggest lender, expects the buyer to pay 3-3.5 times book value of the business, which could make it one of the most expensive non-life insurance deals in Southeast Asia, the people said.

One person estimated the deal value at up to $500 million.

Tokio Marine, Japan’s largest property and casualty insurer by market value, has been the most aggressive among its peers in expanding its global footprint as it fights a shrinking market at home. The planned deal builds upon an exclusive distribution agreement with RHB Bank to sell life insurance products in Malaysia.

Insurers are among the most acquisitive companies in Japan. Tokio Marine alone has spent more than $15 billion on international deals since 2008. That includes U.S. insurers HCC Insurance Holdings Inc for $7.5 billion last year, Philadelphia Consolidated for $4.7 billion in 2008 and Delphi Financial for $2.7 billion in 2012.

Tokio Marine officials were not immediately available for comment, while RHB did not offer an immediate comment. Sources declined to be identified as the information has not been disclosed by the companies.

RHB had initially planned to run a competitive sale process to find the buyer for the general insurance unit, but last week it entered into exclusive talks with Tokio Marine, the people added.

Several other global insurers are still keen to buy the RHB unit if Tokio Marine fails to meet RHB’s price expectations, the people added.

RHB shares were up 1.4 percent in Tuesday afternoon trade, while the benchmark Malaysian share index was down 0.3 percent. Prior to news of the talks, Tokio Marine shares ended down 0.3 percent.

Germany’s Allianz was the top general insurer in Malaysia last year, while MSIG Insurance, owned by Japan’s Sumitomo Mitsui Financial Group ranked second and domestic player AmGeneral Insurance was third. Tokio Marine was No. 7 last year, according to industry association data.

Malaysia’s general insurance market grew 3 percent in the first half of this year, with gross premiums reaching 9.34 billion ringgit ($2.3 billion), while underwriting profit for the sector jumped 11 percent to 836 million ringgit.

The country’s economic growth is, however, slowing as global demand for commodities remains weak and the General Insurance Association of Malaysia has said it expects the second half to be challenging. ($1 = 4.0520 ringgit) (Reporting by Denny Thomas in Hong Kong and Taiga Uranaka in Tokyo; Additional reporting by Liz Lee in Kuala Lumpur; Editing by Stephen Coates and Edwina Gibbs)